Temperature regulation by hypothalamic proportional control with an adjustable set point

Hammel, H. T.; Jackson, Donald C.; Stolwijk, J. A. J.; Hardy, James D.; Strømme, S. B.

doi:10.1152/jappl.1963.18.6.1146

Cited by 310 publications

(90 citation statements)

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“…However, he insisted he was healthy, so we carried out the experiment. The CIZ of Subject D was consequently zero, in support of the set point theory (Hammel et al, 1963). In his case, the sweating threshold was observed 15 min after the beginning of exercise, and T re continued increasing for 5 min and then decreased gradually until shivering occurred.…”

Section: Ciz At a Brightness Level Of 18 Cd/m 2 In Winter And Summersupporting

confidence: 59%

The Effect of Season and Light Intensity on the Core Interthreshold Zone

Kakitsuba

Mekjavic

Katsuura

2011

J Physiol Anthropol

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The hypothesis tested in the present study is a seasonal difference in the core interthreshold zone (CIZ), as we suggested in an earlier study that individual awareness of heat may change the CIZ due to thermoregulatory behavior. A series of human experiments were carried out in a climatic chamber in January and August of 2009 and January of 2010. The air temperature in the chamber was controlled at 20-24°C. Subjects wore a water-perfused suit that was perfused with 25°C water at a rate of 600 cc/min. They exercised on an ergometer at 50% of their maximum work rate for 10-15 min until their sweating rate increased and then remained seated without exercise until oxygen uptake increased. Subjects' rectal temperature and skin temperatures at four sites were monitored by thermistors. The sweating rate was measured at the forehead with a sweat rate monitor (SKD 4000, Skinos Co.). Oxygen uptake was monitored with a gas analyzer (Respiromonitor RM-300i, Minato Med. Science Co.). In the 2009 winter experiment, 5 male subjects were exposed to lighting of 36 cd/m 2 /1,050 lx, and in the 2009 summer and 2010 winter experiments, 10 male subjects were exposed to lighting of 18 cd/m2/510 lx. The results showed that the CIZ of 0.69Ϯ0. 29°C (nϭ22, data from 2005-2007 experiments) at 36 cd/m 2 and that of 0.37Ϯ0.17°C (nϭ10) at 18 cd/m 2 in summer were greater than the CIZ of 0.37Ϯ0.13°C (nϭ5) at 36 cd/m 2 and that of 0.18Ϯ0.17°C (nϭ10) at 18 cd/m 2 in winter, and thus demonstrated a seasonal difference in the CIZ as well as an effect of lighting conditions on the CIZ.

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Section: Ciz At a Brightness Level Of 18 Cd/m 2 In Winter And Summersupporting

confidence: 59%

The Effect of Season and Light Intensity on the Core Interthreshold Zone

Kakitsuba

Mekjavic

Katsuura

2011

J Physiol Anthropol

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“…In general, the reaction is similar to that seen in other species on brief exposure to light. In the monkey, opening and closing the eyes are accompanied by a rise and fall of brain temperature, respectively (HAMMEL et al, 1963), and increases of brain temperature in response to light flashes have been observed in the cat (HULL et al, 1965). Similarily, longer lasting illumination has a positive effect on deep body temperature in the sparrow (BINKLEY et al, 1971), and shorter pulses of darkness lower oxygen consumption in passerine birds (MERKEL, 1958).…”

Section: Discussionmentioning

confidence: 81%

Circadian Rhythms of Brain Temperature in the Chicken, Measured at Different Levels of Constant Illumination

Aschoff

Paul

1973

Jpn.J.Physiol

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Summary 1) Temperature was recorded continuously at various depths in the brain tissue of unanesthetized but moderately restrained chickens. The chickens were kept in a small round arena within a soundproof chamber and exposed to constant illumination for up to 18 days. Activity on a spring-suspended floor in the arena was recorded on print-out counters. Light intensity was varied from 0.05 to 100 lux, but was kept constant for at least 24 hr and in most experiments for several days.2) The brain temperature and most of the activity of all chickens showed clear circadian rhythms. For each condition, the following parameters were computed : mean level of brain temperature, range of circadian oscillation, and amount of activity. 3) Level of brain temperature and amount of activity were positively correlated with light intensity. For the range of brain temperature oscillation, such a correlation was indicated by one statistical test, but the correlation was not significant with increased intensity in two other tests. 4) Range of oscillation seemed to be positively correlated with brain temperature levels at lower values, and negatively correlated at higher values of mean level. 5) The changes in brain temperature in response to changes in light intensity were rather abrupt and simultaneous in all parts of the tissue.In most of the species studied so far, the period of the free-running circadian rhythm depends systematically on light intensity (HOFFMANN, 1965). Little is known about other rhythm parameters' such as range (= difference between maximum and minimum within one period) and mean level (= arithmetic average of all instantaneous values measured within one period). From activity records, the ratio between activity time and rest time, as well as the amount of activity per period, have been computed as subsidiary quantities (ASCHOFF and WEVER, 1962).

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“…Thus, it is considered that the blood pressure responses to concurrent activation of muscle mechanoreceptors and metaboreceptors in different limbs were the result of the integration of these two afferents in the NTS and/or RVLM in the medulla oblongata in the present study. Conversely, the sweating efferent signal may have arisen from the hypothalamus, which is a thermoregulatory control center (16,17,32). Somatosensory afferent signals connect with the paraventricular nucleus of the hypothalamus through the spinohypothalamic tract or through brain stem activation (34).…”

Section: Discussionmentioning

confidence: 99%

Sweating response to passive stretch of the calf muscle during activation of forearm muscle metaboreceptors in heated humans

Amano

Ichinose

Nishiyasu

et al. 2014

American Journal of Physiology-Regulatory, Integrative and Comp

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-Activation of muscle metaboreceptors and mechanoreceptors has been shown to independently influence the sweating response, while their integrative control effects remain unclear. We examined the sweating response when the two muscle receptors are concurrently activated in different limbs, as well as the blood pressure response. In total, 27 young males performed passive calf muscle stretches (muscle mechanoreceptor activation) for 30 s in a semisupine position with and without postisometric handgrip exercise muscle ischemia (PEMI, muscle metaboreceptor activation) at exercise intensities of 35 and 50% of maximum voluntary contraction (MVC) under hot conditions (ambient temperature, 35°C, relative humidity, 50%). Passive calf muscle stretching alone increased the mean sweating rate significantly on the forehead, chest, and thigh (SRmean) and mean arterial blood pressure (MAP), but not the heart rate (HR), from prestretching levels by 0.04 Ϯ 0.01 mg·cm 2 ·min Ϫ1 , 4.0 Ϯ 1.3 mmHg (P Ͻ 0.05), and Ϫ1.0 Ϯ 0.5 beats/min (P Ͼ 0.05), respectively. The SRmean and MAP during PEMI were significantly higher than those at rest. The passive calf muscle stretch during PEMI increased MAP significantly by 3.4 Ϯ 1.0 and 2.0 Ϯ 0.7 mmHg for 35 and 50% of MVC, respectively (P Ͻ 0.05), but not that of SRmean or HR at either exercise intensity. These results suggest that sweating and blood pressure responses to concurrent activation of the two muscle receptors in different limbs differ and that the influence of calf muscle mechanoreceptor activation alone on the sweating response disappears during forearm muscle metaboreceptor activation. nonthermal factors; group III and IV muscle afferents; thermoregulation; sympathetic nervous system; sweat gland THE SWEATING RESPONSE DURING exercise is controlled not only by core and skin temperatures (thermal factors) but also by exercise-related (nonthermal) factors, such as afferent inputs from working muscles. It is well known that group III muscle afferents are stimulated predominantly by mechanically sensitive muscle mechanoreceptors, whereas group IV muscle afferents are stimulated mainly by chemically sensitive muscle metaboreceptors. Activation of muscle metaboreceptors by postexercise muscle ischemia (PEMI) under normothermic and mildly hot conditions induces sweating (2, 4, 22, 38). Additionally, Kondo et al. (23) reported that activating the muscle mechanoreceptors by passive limb movement for 2 min evoked slight sweating under hot conditions. Furthermore, the muscle mechanoreflex increases the sweating response during passive recovery (passive limb movement using a tandem ergometer) compared with inactive recovery (resting) after cycling (20,39). These studies suggest that the isolated activation of muscle metaboreceptors and mechanoreceptors can independently affect sweating responses. However, the sweating response is presumably controlled by integrative mechanisms, based on afferent signals from muscle metaboreceptors and mechanoreceptors because physiological integrative control h...

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Temperature regulation by hypothalamic proportional control with an adjustable set point

Cited by 310 publications

References 0 publications

The Effect of Season and Light Intensity on the Core Interthreshold Zone

The Effect of Season and Light Intensity on the Core Interthreshold Zone

Circadian Rhythms of Brain Temperature in the Chicken, Measured at Different Levels of Constant Illumination

Sweating response to passive stretch of the calf muscle during activation of forearm muscle metaboreceptors in heated humans

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